McPherson holds that duty, honor, patriotism and ideology produced the major sustaining motivations for the Civil War, while courage, self-respect and group cohesion kept men going in combat. Yet all of this morale and motivation relied on support from home. Without home support, the Civil War soldiers would have fallen apart. Homesickness is an omnipresent theme in the writings of Civil War soldiers. Efficient mail services helped to keep morale high; both armies understood the importance of effective communication. Mail call was the happiest moment of each soldier's day, and they often criticized their family members for not writing enough.

Letters were crucial to sustain soldiers, but bad letters had the opposite effect. Wives would often complain that they were lonely and suffering, or that they were worried that the war would leave them widows. They were full of dread...